Building permits, zoning and land rules in Iron County, Utah

Yes. Iron County requires a building permit for structural, electrical, plumbing or mechanical work that the county administers, including new construction, additions, remodels and utility upgrades¹. An accessory structure no larger than 200 square feet can avoid a building permit only when it has no electrical, plumbing or mechanical work; anything larger requires a permit¹. Unincorporated construction is governed by codes Iron County adopts as amended by Utah, and the statewide construction code applies to new construction and qualifying changes to existing buildings^13,14.

A structure used solely for agriculture and not for human occupancy can qualify for State Construction Code relief, but plumbing, electrical or mechanical permits may still be required¹⁵. The exception has parcel-location and acreage conditions inside cities and county-approved subdivisions¹⁵. Iron County issues a final certificate of occupancy only after required construction and grading work is complete and the listed compliance documents and applicable city signoff are in place¹⁶.

The Iron County Building Department issues county building permits and can be reached at 435-865-5350 or building.group@ironcountyut.gov at 82 N 100 E #102, Cedar City, Utah 84720¹. Inside Cedar City, the city issues building permits; Southwest Utah Public Health Department remains the septic authority^3,5. Applications, online payment and inspection scheduling are available through the county's building permit portal¹. An inspection request needs the permit holder's name, permit number and project address¹. Iron County inspects building, electrical, plumbing, mechanical and fuel-gas phases; if an inspector issues a correction notice, work cannot move to the next phase until the corrections pass reinspection¹⁷.

Iron County publishes a fee schedule, but the permit FAQ does not state one flat project price¹. Plan-review fees are nonrefundable, building-permit fees are not refunded after 180 days, and a project with no required inspection completed within 1 year must be renewed under the fee schedule¹. Zoning questions go to the separate Iron County Planning Department at 435-865-5386¹⁸.

Iron County administers zoning on unincorporated land; use the county Zoning Map with the assessor parcel number or property account number, then confirm the proposed use with Planning^1,2,18. Cedar City and Parowan set their own zoning; Southwest Utah Public Health Department remains the septic authority throughout Iron County^4,5,19. Unsewered residential subdivision lots generally need at least 5 acres unless they use a cluster or maximum-density option⁷. In A-20 and RA-20, legally created or pre-August 14, 2000 lots below 20 acres have special rules; listed uses on lots below 15 acres require conditional-use treatment⁸.

In unincorporated Iron County, chassis-retaining manufactured homes require HUD standards, a permanent foundation, at least 12 feet of width and more than 500 square feet; the table lists residential and agriculture zones and R4K⁸. Pre-1976 mobile-home placements are limited to existing Beryl mobile-home parks⁸. ADUs are permitted in A-20, RA-20, RR-20, R-5, R-2, R-1 and R-1/2, but prohibited in R4K, C, LI, I and IA⁸. ADUs also require owner occupancy, shared utilities, adequate septic capacity, parking and compliance with size and rental-duration limits²⁰.

Southwest Utah Public Health Department is the local authority for onsite wastewater permitting, plan review, inspections and records in Iron County⁵. A permit and approved design are required before a septic system is installed, replaced or modified, and soil and percolation testing must be completed by a Utah-certified onsite professional before design or installation⁵. Iron County applications also require Utah Division of Wildlife Resources documentation clearing the property for prairie-dog habitation⁵.

Every installed septic system must receive a final inspection before backfilling, scheduled through Environmental Health²¹. Only 17% of Iron County soils are rated without severe limitations for a conventional drain field, so treat septic feasibility as a pre-purchase question rather than assuming a standard gravity system will work²². Residential lots in subdivisions without public sewer generally must be at least 5 acres, unless they are part of a cluster or maximum-density subdivision⁷. Utah requires wastewater to go to either a public sewer or a permitted onsite system; a septic system is a lawful off-grid sanitation route, not a permit-free one⁵.

Iron County does not treat an RV or travel trailer as a year-round dwelling, and temporary RV use is permitted in some unincorporated zoning districts but prohibited in others⁸. Temporary camping on a qualifying legal lot is limited to 1–16 days in a 30-day period, with sanitation, garbage, fire and waterbody setbacks²³. Seasonal RV use for 17–180 days requires qualifying restricted seasonal access, a building permit, approved site plan, sewage arrangements, culinary water and solid-waste service²³. The separate mobile-home rule limits living or sleeping outside established parks to temporary or seasonal periods unless the building official grants the specified utility, waste-service and winter-protection exception⁹.

In unincorporated Iron County, wheeled tiny homes and park models are listed only for travel-trailer parks, with a maximum area of 500 square feet⁸. Wheeled tiny homes may be at most 8 feet 6 inches wide; park models must be at least 8 feet wide and meet ANSI A-119.5-15⁸. Manufactured or modular tiny homes on permanent foundations are listed for R4K at 500 square feet or less, subject to district standards and building permits⁸. Ask Iron County Planning to confirm the parcel's district and dwelling category before purchase¹⁸.

1. Confirm whether the parcel is unincorporated, look up its district on the Iron County Zoning Map using the assessor parcel number or property account number, then ask Planning to confirm the allowed dwelling type, setbacks and required land-use approvals^1,4,18.
2. Verify legal water. A private well requires a valid water right and State Engineer permission before regulated construction, followed by work from the appropriately licensed well professional¹¹.
3. Complete septic soil and percolation testing, obtain prairie-dog clearance documentation, and secure the health department's approved design and permit⁵.
4. Resolve access. The first public-road or county-right-of-way access for a new home is approved with the building permit; additional access needs an encroachment permit¹². A connection to a state highway requires UDOT's conditional access permit²⁴.
5. Submit the building-permit application and plans, then schedule required inspections through the portal; correct any cited problems and pass reinspection before moving to the next construction phase^1,17.
6. Arrange the septic final inspection before backfilling and complete all building closeout items before occupancy^16,21.

Start with zoning, subdivision status, legal access, water rights and septic feasibility. Iron County Planning can identify the unincorporated zoning district, land-use rules and subdivision issues^6,18,25. In the A-20, RA-20 and RR-20 districts, qualifying road right-of-way can count toward the 20-acre minimum, but the credit is limited to 2 acres and carries location conditions⁸. An approved R-1/2 Performance Subdivision Option uses its own lot, setback, separation, height and coverage standards⁸. The Engineering Department handles county-road access, while UDOT controls state-highway connections^12,24.

A domestic well requires a valid water right and State Engineer authorization¹¹. Only 17% of county soils avoid a severe conventional-drain-field limitation²². Manufactured homes in special flood-hazard areas must be elevated and anchored under the county's stated conditions²⁶. The broader floodplain development permit requirement remains unconfirmed, so ask Engineering about mapped hazards and review before closing.

Iron County Greenbelt treatment assesses qualifying farmland by productive capability; eligibility generally requires at least 5 contiguous acres, agricultural use for the preceding 2 years and production requirements, with stated exceptions²⁷. New applications are due May 1; development or non-use can trigger rollback tax for up to 5 preceding years²⁷.